It is clear from this Rashi that had the Bnei Yisroel davened incorrectly and said, “HASHEM save us from Canaan,” their tefillah would not have worked. However, they were saved because they realized the trick and davened in a manner that included all possibilities.
This Rashi is very difficult to understand. What difference would it make what expression the Jews used? HASHEM would know what they meant. The Jewish nation was in trouble, faced with an enemy attacking, and they called out to their Creator. Why would it matter whether they referred to the attackers as Canaan or Amalek? HASHEM would know what they were referring to, and if they were worthy of being saved, HASHEM would listen.
The answer to this question cuts to the very underpinning of how prayer works.
